In most mammals like humans, the fetus produced as a result of the fertilization of the sperm and egg, develops in the uterus or womb of the female. However, this developing fetus cannot yet fend for what it requires for survival and is still dependent on the mother e.g nutrients, oxygen etc. How do this substances get to the fetus? Here comes the role of the PLACENTA.
Placenta is an organ in the uterus that serves as a connection between the mother and the fetus in her womb. The placenta enables the mother to pass digested nutrients to the fetus and exchange gases (oxygen and Carbondioxide) between them via the umbilical cord. The placenta also enables the mother remove waste produced by the fetus into her bloodstream.
Answer - A Semi-conservative model of replication involves the replication of DNA in all the familiar cells in such a way that each newly synthesized daughter cell contains a double helix with one new strand and one old strand.
This is because your corpus collosum is the brand of nerve fibers that join the two hemisphere of your brain, if it was severed, your post central gyrus would not know what your left hand was doing because the corpus collosum is part of the connection that helps your brain register the information.
polarity of a molecule deals with the presence of net charges and partial charges. this has nothing to do with its symmetry which is determined by the molecule's structure